This invention relates to bicycle-frames, and more specifically it relates to tubular-metal types of bike frames having non-articulated shock & vibration seat supporting structure built-in to the frame.
Heretofore, it common knowledge that tubular bike-frame construction without benefit of articulated front or rear suspension, can impose considerable punishment unto the rider, particularly directed to the rider's pelvic-coccyx region; as well as imposing possible roadability dificulties. This problem has been ameliorated to some extent via pneumatic balloon-tires, and to a greater extent via independent wheel suspension systems; -but owing to weight restrictions and rolling-friction factors, these advancements have been relegated to use primarily among bicycles of the mountain-bike classification, where severe pounding off-road conditions necessarily dictate provision of both.
Background research discovery provides a particularly germane prior patent art regarded as material to this disclosure, in that U.S. Pat. No. 4,934,724 (filed: April, 1989, to Allsop Bike-Co.), contemplates several variations on a "combination beam seat support" of composite-plastic solid foam-core construction; including employment of an elastomeric material at both the forward nose anchor point and the mid-length point of longitudinal mounting to the bicycle frame. Additionally, the inventor clearly points out how each of the different generic-variant embodiments employs a sheer-gap provision, whereby the elastomeric substance bonds the upper and lower halfs together in a manner believed facilitating increased vertical bending of the seat beam; so that the rider, poised upon the saddle located at the extreme aftward end of the cantilevered beam, enjoys a substantially improved quality of ride, -owing to the shock-absorption ability of the aggregate structure.
The Allsop Beam-seat, and more recently, the Zipp-2001 (with monocoque carbonfiber-frame having a fully integrated aftwardly cantilevered seat-support) while offering good performance, are obviously predicated upon the premise that only carbonfiber composite-plastic construction can achieve such an extraordinary cantilevering strength characteristics, within the constraints of weight generally imposed upon high performance bicycle construction. There thus still remains however, need for an alternate type of light weight cantilevered beam-seat apparatus employing novel hollow tubular construction, heretofore eluding bicycle fabricators internationally.
Accordingly, the instant inventor hereof has developed an all titanium racing-bicycle employing an improved cantilevered-seat configuration employing tesil-stress rather than compression-stress in bending; along with a special abreviated frame rolling on 700 cm-wheels with an overall weight of only 16.8 lbs. This bike has already won significant race competitions on weekends, while providing reliable commuting service during weekdays; and, is currently in initial production as the TitanFlex.TM., under the auspices of the AiroSeries-Mfg/Mkt. Co., SanDiego, Calif.